Three-tier collapsible cooling rack



FIG. 1 is a perspective view of the improved three-tier collapsible cooling rack;

FIG. 2 is a top view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is a back side view thereof;

FIG. 6 is a second side view thereof; and,

FIG. 7 is a bottom view thereof. 

The ornamental design for the “improved three-tier collapsible cooling rack,” as shown and described. 